This alert expired on 16 May 2026 at 21:30 UTC. It is kept here as a record.
It is the 2nd strongest of the 51 detections recorded within 20 km of this point since 15 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 16 at 3:39PM CDT until May 16 at 4:30PM CDT by NWS St Louis MO
An estimated 112,617 people live within 50 km of this point.
Nearby, since 15 March 2026
- May 18, 2026 · score 34 · 5.7 km
- May 17, 2026 · score 34 · 5.7 km
- May 15, 2026 · score 34 · 5.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 out of 100, at 80 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 80% |
| Coordinates | 38.5991, -89.4257 |
| Nearest City | O'Fallon (42 km) |
| Population Exposed | 112.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-16T20:39:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.1008d7844e784662abaa5bbf3bea28a6 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Clinton, IL; St. Clair, IL; Marion, IL |
| Headline | Severe Thunderstorm Warning issued May 16 at 3:39PM CDT until May 16 at 4:30PM CDT by NWS St Louis MO |
| Expires | 2026-05-16T16:30:00-05:00 |
| SenderName | NWS St Louis MO |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.1008d7844e784662abaa5bbf3bea28a6c9780c07.001.1","noaa_urn:oid:2.49.0.1.840.0.0ae54363294621650fe9f122b857b9c5df5d6bee.001.1","noaa_urn:oid:2.49.0.1.840.0.cf73527e5daf805118190de4a4cf46cb9ff1c505.001.1"] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 10 February 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Calamity.live data shows a weather event with CalamityScore 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.